ARGATROBAN IN POST-CARDIOVASCULAR SURGERY PATIENT WITH HEPARIN-INDUCED THROMBOCYTOPENIA REQUIRING HEMODIALYSIS AND CONTINUOUS HEMOFILTRATION
Keith K Lau, Eric J Escue, Bettina H Ault, Deborah P Jones, and Stephanie A Storgion

OBJECTIVE: To describe the use of argatroban in a postoperative cardiovascular surgery patient with heparin-induced thrombocytopenia (HIT) requiring hemodialysis and continuous veno-veno hemofiltration (CVVH).

CASE SUMMARY: A 23-year-old white woman with HIT developed acute renal failure after cardiovascular surgery. Argatroban was used as a substitute for heparin during hemodialysis and CVVH. Both activated partial thromboplastin time (aPTT) and activated clotting time (ACT) were used to guide the dosage of argatroban. The patient was successfully dialyzed without clotting of the circuit. The dosage required in our patient was much lower than the manufacturer's recommendation.

DISCUSSION: Argatroban is a selective thrombin inhibitor that does not cross-react with heparin-induced antibodies. It is metabolized by the liver, and dosage adjustment is recommended in patients with severe hepatic impairment. The correct dosage for patients with unstable hemodynamics is not known. Our patient had apparently normal hepatic function at the initiation of therapy, but the dosage of argatroban recommended by the manufacturer resulted in prolonged elevation of the aPTT and ACT with associated gastrointestinal bleeding. This may be due to hepatic congestion secondary to poor cardiac function and/or severe generalized edema.

CONCLUSIONS: When argatroban is considered for therapy in place of heparin for CVVH, it needs to be used with extreme caution since the correct initial dosage in patients with mild hepatic impairment and unstable hemodynamics is unclear.

J Pharm Technol 2005;21:213-6.